Vulnerability · Published Oct 22, 2026 · Assigned by Checkmarx
CVE-2026-77156ast-cli: Path traversal in tar extraction on Linux/macOS allows writes outside the install directory
Medium 6.4
In plain English
A medium-severity path traversal in github.com/checkmarx/ast-cli from Checkmarx. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 29% of all known vulnerabilities).
Official description
Incomplete validation of extracted archive entry paths in ast-cli's tar extraction logic on Linux and macOS (used when installing the Vorpal ASCA real-time engine and the SCA Resolver) would allow a malicious tar archive containing absolute or traversal path entries to write files outside the install directory. Windows builds were not affected, as the Windows extractor performs this path validation. Exploitation required substituting the archive served at "download.checkmarx.com". An attacker able to compromise that server and replace the archive could write arbitrary, executable files to arbitrary filesystem paths via this path traversal. Extraction now validates that each entry's destination path resolves within the working directory and rejects absolute paths.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Checkmarx | github.com/checkmarx/ast-cli | 0 – before 2.3.51 |
Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H